#region Apache License
//
// Licensed to the Apache Software Foundation (ASF) under one or more 
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership. 
// The ASF licenses this file to you under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with 
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#endregion

using System;

namespace log4net.Util.TypeConverters
{
    /// <summary>
    /// Convert between string and <see cref="PatternString"/>
    /// </summary>
    /// <remarks>
    /// <para>
    /// Supports conversion from string to <see cref="PatternString"/> type, 
    /// and from a <see cref="PatternString"/> type to a string.
    /// </para>
    /// <para>
    /// The string is used as the <see cref="PatternString.ConversionPattern"/> 
    /// of the <see cref="PatternString"/>.
    /// </para>
    /// </remarks>
    /// <seealso cref="ConverterRegistry"/>
    /// <seealso cref="IConvertFrom"/>
    /// <seealso cref="IConvertTo"/>
    /// <author>Nicko Cadell</author>
    internal class PatternStringConverter : IConvertTo, IConvertFrom
    {
        #region Implementation of IConvertTo

        /// <summary>
        /// Can the target type be converted to the type supported by this object
        /// </summary>
        /// <param name="targetType">A <see cref="Type"/> that represents the type you want to convert to</param>
        /// <returns>true if the conversion is possible</returns>
        /// <remarks>
        /// <para>
        /// Returns <c>true</c> if the <paramref name="targetType"/> is
        /// assignable from a <see cref="String"/> type.
        /// </para>
        /// </remarks>
        public bool CanConvertTo(Type targetType)
        {
            return (typeof(string).IsAssignableFrom(targetType));
        }

        /// <summary>
        /// Converts the given value object to the specified type, using the arguments
        /// </summary>
        /// <param name="source">the object to convert</param>
        /// <param name="targetType">The Type to convert the value parameter to</param>
        /// <returns>the converted object</returns>
        /// <remarks>
        /// <para>
        /// Uses the <see cref="PatternString.Format()"/> method to convert the
        /// <see cref="PatternString"/> argument to a <see cref="String"/>.
        /// </para>
        /// </remarks>
        /// <exception cref="ConversionNotSupportedException">
        /// The <paramref name="source"/> object cannot be converted to the
        /// <paramref name="targetType"/>. To check for this condition use the 
        /// <see cref="CanConvertTo"/> method.
        /// </exception>
        public object ConvertTo(object source, Type targetType)
        {
            PatternString patternString = source as PatternString;
            if (patternString != null && CanConvertTo(targetType))
            {
                return patternString.Format();
            }
            throw ConversionNotSupportedException.Create(targetType, source);
        }

        #endregion

        #region Implementation of IConvertFrom

        /// <summary>
        /// Can the source type be converted to the type supported by this object
        /// </summary>
        /// <param name="sourceType">the type to convert</param>
        /// <returns>true if the conversion is possible</returns>
        /// <remarks>
        /// <para>
        /// Returns <c>true</c> if the <paramref name="sourceType"/> is
        /// the <see cref="String"/> type.
        /// </para>
        /// </remarks>
        public bool CanConvertFrom(System.Type sourceType)
        {
            return (sourceType == typeof(string));
        }

        /// <summary>
        /// Overrides the ConvertFrom method of IConvertFrom.
        /// </summary>
        /// <param name="source">the object to convert to a PatternString</param>
        /// <returns>the PatternString</returns>
        /// <remarks>
        /// <para>
        /// Creates and returns a new <see cref="PatternString"/> using
        /// the <paramref name="source"/> <see cref="String"/> as the
        /// <see cref="PatternString.ConversionPattern"/>.
        /// </para>
        /// </remarks>
        /// <exception cref="ConversionNotSupportedException">
        /// The <paramref name="source"/> object cannot be converted to the
        /// target type. To check for this condition use the <see cref="CanConvertFrom"/>
        /// method.
        /// </exception>
        public object ConvertFrom(object source)
        {
            string str = source as string;
            if (str != null)
            {
                return new PatternString(str);
            }
            throw ConversionNotSupportedException.Create(typeof(PatternString), source);
        }

        #endregion
    }
}
